C2: Reactions- Key Concepts Flashcards
nucleophiles are ____ and want a ____ charge
electron rich; positive
the requirements for a nucleophile are:
- to have a ____ charge OR a ____ charge
- a ___ OR ____ bond electrons
- full negative; partial negative
- lone electron pair; pi
nucleophiles ____ a pair of electrons and form a ____ bond. they are lewis ____
donate; covalent; bases
when comparing the same atom, a more ___ charge makes a stronger nucleophile
negative
for atoms in the same period on the periodic table, nucleophilicity ____ as electronegativity decreases
increases
when comparing atoms in the same family, nucleophilicity ____ as size increases
increases
electrophiles are electron ____
deficient
electrophiles have a full ____ charge OR a partial _____ charge
positive; positive
electrophiles ____ a pair of electrons and acquire a ____ bond. they are lewis ____
accept; covalent; acids
good leaving groups have a ____ C-LG bond to start, are ____ and are electron ____ groups. they are also stable and unreactive once gone and ____ or very ____ bases, are stabilized via ____, and are large and can polarize ____ charge.
weak; electronegative; withdrawing; neutral; weak; resonance; negative
a bad leaving group is a ____ base but can be made into a good leaving group via ____
strong; protonation
another bad leaving group is ____ but can be made into a good leaving group in 3 ways which are…
hydroxide
- tosylation (OH’s changed to OT’s)
- mesylation (OH’s changed to OM’s)
- switch it to a halide (OH’s are changed to halogens)
carbocations are electron ____ (deficient/ rich) and are stabilized by electron ____ (donating/withdrawing) groups
deficient; donating
radicals are electron ____ (deficient/ rich) and are stabilized by electron ____ (donating/withdrawing) groups
deficient; donating
carbanion are electron ____ (deficient/ rich) and are stabilized by electron ____ (donating/withdrawing) groups
rich; withdrawing
stability ____ with carbocations (secondary, tertiary, quaternary). unstable carbocations can undergo ____ to a directly adjacent and ____ order carbon which ____ the stability of the carbocation
increases; rearrangement; higher; increases
in order for stability of a carbocation to increase, there are 2 options…
- both of these options have the same conclusion…
- hydride shift
- methide shift
- they can only shift directly to the carbon next door and are shifting to get a higher order (ex: secondary to tertiary)
what is a regiospecific rxn?
- selective species are ____ to react and favor more ____ intermediates
a rxn that produces one constitutional isomer and often involves the use of selective species (favor producing stable intermediates)
- slower; stable
what is a non-regiospecific rxn?
- reactive species are ____ to react and choose a location where it will ____
a rxn that produces more than one constitutional isomer and often involves the use of reactive species
- faster; react better
what does a stereospecific rxn produce?
one stereoisomer that is EITHER:
R or S
cis or trans
E or Z
what does a nonstererospecific rxn produce?
more than one stereoisomeric product that is:
R and S
cis and trans
E and Z
for SN2 and SN1 reactions, describe the following difference for each:
# of steps
- SN2
- SN1
- 1
- at least 2
for SN2 and SN1 reactions, describe the following difference for each:
electrophile
- SN2
- SN1
- smaller is better
- more substituted is better
for SN2 and SN1 reactions, describe the following difference for each:
nucleophile
- SN2
- SN1
- strong and small
- weak is ok
